Digital Signal Processing (DSP) based optical coherent receivers have emerged as a suitable solution for 100 Gigahertz (G) and above long-haul optical transport, due to their ability to restore the optical field of a received optical signal. The 100 G coherent receiver is designed to receive an optical signal centered on a single wavelength grid. However, there is a need for a single coherent receiver design that can detect multiple optical wavelength channels, e.g., wavelength division multiplexing (WDM) channels, simultaneously. Such design is advantageous since it allows sharing and simplifying of electro-optics and DSP hardware among the multi-wavelength channels (e.g., WDM channels), and reduces the implementation cost.